The EU is resuming action at the WTO against the United States in a dispute over subsidies to Airbus and Boeing, EU trade chief Peter Mandelson said, adding he was "confident" of the bloc's case.
"In order to sustain conditions for fair competition in civil aircraft production and to maintain a proper commercial balance between the two companies, the European Union is today resuming action in the WTO to confirm through a panel the illegality of subsidies paid to Boeing" Mandelson said Tuesday.
"I am confident about the strength of Europe's case," he added.
The move comes after Washington said that it would ask the WTO on Tuesday to create an arbitration panel to resolve a dispute over European subsidies to aircraft maker Airbus.
Mandelson warned that a stand-off at the WTO was likely to bring one of the longest and most costly legal battles in the history of the frree trade body.
The EU and the US both filed WTO suits against each other in October but agreed in January to shelve action in order to seek a negotiated deal rather than face a costly legal battle.
The simmering dispute over aid to Airbus and Boeing has become inflamed lately after Airbus requested British government aid for its A350 long-haul plane designed to compete with Boeing's plans to launch the 787 Dreamliner.
The United States believes financial aid given to Airbus to launch new aircraft is illegal, while the Europeans accuse Washington of subsidising Boeing through military contracts.